Fenix, a popular third-party Twitter app for Android, has been pulled from the Google Play Store after hitting Twitter's token limit. Token restrictions limit the number of users that a third-party Twitter app can have.
The official Fenix account announced the move on Twitter:
Unfortunately, starting from yesterday, Fenix cannot be used by any more new users (due to the infamous Twitter tokens limitation).— Fenix (@fenix_app) April 25, 2016
The app has been removed from the Play Store, but current users can continue to use it with no issues.— Fenix (@fenix_app) April 25, 2016
If you're currently using the app, you'll continue to be able to do so. You can also re-download Fenix from the "My apps & games" section in the Play Store if you need to.